Bone Plate and Bone Plate Assemblies Including Polyaxial Fasteners

ABSTRACT

A system for fixation of bone, including a bone plate with an opening comprising threads made of a first material and a fastener with a head at least partially comprising a polymeric material that is softer than the first material. In some embodiments, when the fastener is inserted into the first opening, the threads of the first opening form threads in the polymeric material on the head of the fastener and secure the fastener in place at one of a plurality of possible angles within the first opening. The first opening additionally accepts a fastener with a substantially spherical head for compression of a fracture, or a fastener with a threaded head that engages with the threads of the threaded opening. In some embodiments the first opening includes a substantially frustoconical-shaped top portion. In other embodiments there may be a second opening that is either non-threaded or comprises a plurality of protruding fins.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/996,795 filed Jan. 25, 2008 and entitled “Polyaxial Plate,” which isa national phase application of PCT Application Ser. No.PCT/US2006/028778 filed Jul. 25, 2006 and entitled “Systems & Methodsfor Using Polyaxial Plates,” which claims the benefit of U.S.Provisional Application Ser. No. 60/702,231, filed Jul. 25, 2005 andentitled “Locking Screw,” and is further a continuation of U.S.application Ser. No. 11/644,306, filed Dec. 22, 2006 and entitled “BonePlates and Bone Plate Assemblies,” which is a continuation of U.S.application Ser. No. 10/673,833, filed Sep. 29, 2003 and entitled “BonePlates and Bone Plate Assemblies,” the entire contents of each of whichare hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to orthopedic fixation devicesand bone plating systems for fracture fixation, and particularly tosystems and methods for using polyaxial fasteners within bone platingsystems.

BACKGROUND OF THE INVENTION

Bone fractures are often repaired by securing a bone plate across thefracture. Depending upon which bone is to be treated, the bone plate maybe straight or curved to match the contour of the bone for which it isdesigned. Bone plates may also be provided in many shapes and sizes. Incases where a bone is severely comminuted or if bone segments aremissing, the use of bone plate and screw systems promotes healing of thefracture by providing a rigid fixation or support structure between thebone and the plate.

Bone plates may be secured to the bone in a number of ways. An existingsolution is a plate and screw system where screws, called lockingscrews, are locked in the plate. First, a locking screw is threadedthrough an opening in the plate and into the bone. Then the lockingscrew is secured to the bone plate via threads on the head of thelocking screw that cooperate with threaded openings in the bone plate.This secures the plate with respect to the bone and provides rigidfixation because the relationship between the plate and locking screw(s)is fixed. Because the threads on the head of the locking screwinterdigitate with the threads in the plate opening, the plate andscrews(s) form one stable system, and the stability of the fracture canbe dependent upon the stiffness of the construct. Locking a screw intothe plate can achieve angular and axial stability and eliminate thepossibility for the screw to toggle, slide, or be dislodged, reducingthe risk of postoperative loss of reduction.

However, although locking screws may reduce the incidence of loosening,they have limitations. Locking screws provide only one fixed anglerelationship between the plate and the screw(s). They have a limitedinsertion angle because the threads of the head mate with the threads ofthe hole in one way only. The longitudinal axis of the screw aligns withthe central axis of the hole, and no angular variation is allowed. Inshort, locking screws are unidirectional, limiting their use in someinstances. For example, when treating a severe fracture, bone fragmentsmay be shattered and in irregular positions. Although a surgeon may wishto obtain the benefits of a locking screw and bone plate used together,the pre-determined angle at which the locking screw extends from theplate may not be the angle that would allow the surgeon to “grab” (orseize, or otherwise secure) the desired, random bone fragment. Rather,screws with more angular flexibility (such as compression screws) may berequired. Moreover, locking screws secured in a plate have a limitedcapability to compress bone fragments, since once the screw is fullyrotated to lock with the plate, it can rotate no further to compress theplate to the bone. Conversely, there may be situations where the screwrotates sufficiently to capture bone, but does not rotate sufficientlyto lock to the plate.

In short, while locking screws were useful to provide rigid fixation,they often could not perform other functions typically performed bytraditional non-locking or compression screws (also referred to ascortical or cancellous screws). Although non-locking screws are securedinto bone in the same way that locking screws are, they are not securedto the plate. Their heads are typically rounded where they contact thebone plate and they do not have threads that lock into the plate. Thus,while not optimal in providing a rigid construct between the screw andplate, they can be inserted at various angles because they are notlimited by the thread-to-thread contact of locking screws with the boneplate.

Given the unique contributions of each of locking and non-lockingscrews, bone plating systems were developed that provided surgeons theoption of using both types of screws in an installation. In this way,surgeons could choose intra-operatively whether to use the bone platewith compression screws, locking screws, or a combination of both andthus more effectively tailor the installation to the particularsituation.

In some embodiments, these systems provide plates with some threadedholes (that may receive either locking screws or non-locking screws) andsome non-threaded holes (for non-locking screws). Some systems providepartially threaded slots to allow either non-locking or locking screwsto be used together. Such combination slots provide surgeons with theintra-operative choice about whether to use the plate with lockingscrews, non-locking screws, or a combination of both. These combinationslots typically have a partially threaded opening that can receiveeither a compression screw or a locking screw. However, because thesecombination slots are only partially threaded, the locking screw(s) maynot be able to maintain the fixed angular relationship between thescrew(s) and plate under physiological loads. Specifically, the lockingscrews within the plate are only partially captured and thus onlypartially surrounded by threads. Under high stress and loadingconditions, the slot may distort and allow the fixed angularrelationship between the locking screw and plate to change. This canresult in loss of fixation or loss of established intra-operative plateorientation. Moreover, the locking screw can still only be inserted at asingle angle—the predetermined angle defined by the manufacturer.

Additionally, current bone plate and screw systems still limit asurgeon's ability to both (a) lock a fastener with respect to the boneplate, but still (b) allow the fastener to extend from the bone plate atvarious angles. Locking screws lock into the plate, but only in a singleangular configuration, and non-locking screws allow various angleconfigurations, but they do not provide a stable construct with theplate. Accordingly, none of these options allow a surgeon to capturebone fragments that do not fall in line with the axis of the openingprovided on the plate in a rigid fashion. Thus, currently availableoptions can still lead to mal-alignment and poor clinical results.

There have been some attempts to provide polyaxial locking systems. Forexample, one effort includes providing holes that accept fixed anglelocking pegs and multidirectional locking pegs, with a threaded capinserted over the multidirectional peg to hold it in place. Such asystem can be cumbersome to use because, although the multidirectionalpeg can be inserted at any angle, the surgeon then needs to thread asmall cap onto the top of the peg head and into the plate, requiring anextra step, extra time, and extra instrumentation. Such systems alsofail to allow the use of non-locking members in conjunction with thelocking and multidirectional pegs.

Other systems that have attempted to offer polyaxial fixation includeproviding a bone plate with deformable inserts at the hole peripheriesmade out of a deformable material, with the remaining part of the platemade of titanium. The plate is manufactured and the deformable insertsare then pushed into the hole peripheries and engaged in place bydeformation and pressure. When screws are inserted, the deformableinserts deform and are compressed between the screws and the edges ofthe holes of the plate, which holds the screws and inserts in place.There are challenges with such systems, however. First, the deformableinserts cannot be used with non-locking screws. Second, the deformableinserts do not have the strength to receive and hold a regular lockingscrew. Thus, the unavailability of non-locking screws and regularlocking screws do not provide the surgeon with options. Finally, plateswith deformable inserts are more expensive to manufacture than regularbone plates.

Accordingly, there exists a need for an improved bone plating systemthat overcomes the deficiencies of the prior art. There is a need for asystem that provides a stable connection between a bone and a bone plateusing a fastener that permits different angles to be obtained betweenthe bone plate and the fastener, while the fastener also locks into thebone plate. This would allow surgeons to capture random bone fragmentsthat are in irregular positions, for example, in cases of severefractures with highly fragmented bone fragments. In these and othercases, it would be advantageous to provide a fastener and plate systemthat allows the surgeon to choose the angle at which the screw isinserted through, and rigidly affixed in, an opening of the plate.

Such an improvement would allow a surgeon to direct the fastener towardbone fragments that are not necessarily located directly beneath theopening in the plate. It would also provide flexibility in the placementof the plate in relation to the bone fracture. Allowing surgeons tochoose the angle at which the fastener is inserted into the plate wouldlead to better tailoring of the system to the specific nature of thebone fracture to be treated. It would also allow surgeons to adjusttheir strategy as necessary after the surgical site has been accessed,but prior to insertion of the fastener into bone material. Additionally,embodiments described herein provide for a more secure polyaxialinsertion than what is available in known systems which contain a platewith a deformable insert.

BRIEF SUMMARY OF THE INVENTION

In certain embodiments there is a bone plate comprising a first opening.The first opening may be threaded, and the threads may be made of afirst material. A first fastener may be inserted into the first openingin order to secure the bone plate to the bone. In certain embodimentsthe first fastener has a head at least partially made of a polymericmaterial that is softer than the first material of the threads of thefirst opening. In use, the first fastener is positioned and rotated inthe first opening, and the threads of the first opening form “threads”into the polymeric material of the first fastener to thereby fix theorientation of the first fastener relative to the first opening. Thus,the first fastener may be secured at one of a plurality of possibleangles within the first opening. This may help in capturing “renegade”or random bone fragments that have split from the bone during fracture,and may help in securing the bone fragments to the bone plate.

The first opening is configured to interchangeably accept other types offasteners in addition to the first fastener. For example, there isprovided a second fastener with a threaded head, wherein the threads onthe head are configured and dimensioned to mate with the threads of thefirst opening (also called a locking fastener). In use, when the secondfastener is inserted into the first opening, the threads of the firstopening and the threads on the head of the second fastener engage, which“locks” the second fastener in place within the first opening.

The first opening may additionally accept a third fastener comprising ahead with a substantially spherical and non-threaded portion (alsocalled a non-locking fastener). In use, when the third fastener isinserted into the first opening, the spherical portion of the headcontacts, but does not otherwise engage with, the threads of the firstopening. Thus the third fastener can be inserted at various anglesbecause it is not limited by the thread-to-thread contact with the firstopening.

In certain embodiments the first opening may have a frustoconical-shapedtop portion that helps push or pull the bone plate in a particulardirection as a fastener is inserted into the first opening. Inparticular, the head of a fastener may come into contact with and ridealong the frustoconical-shaped top portion of the first opening, thusmoving the bone plate in a particular direction. In certain embodiments,additional openings may be provided on the bone plate, including othertypes of threaded openings, non-threaded openings, provisional fixationholes, K-wire holes, combination holes, finned openings, and slots. Thedifferent types of fasteners described above—including the first,second, and third fasteners described above—may be used as appropriatein the different types of openings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows perspective view of one embodiment of a fastener of thisinvention.

FIG. 2 shows a cross-sectional view of the fastener of FIG. 1 positionedin a bone plate.

FIG. 3 shows a fragmentary top perspective view of a bone plate havingfins according to one embodiment of the invention with a fastenerinserted therein.

FIG. 4 shows a fragmentary top perspective view of the bone plate ofFIG. 3.

FIG. 5 shows a top perspective view of a bone plate having multipleopenings, with fasteners inserted in two of the plate openings.

FIG. 6 shows a bottom perspective view of the bone plate of FIG. 5.

FIG. 7 shows a side elevational view of the bone plate of FIG. 5.

FIG. 8 shows a perspective view of one embodiment of a fastener for usewith various bone plates described herein.

FIG. 9 shows a top plan view of an alternate embodiment of an openingfor use in a bone plate.

FIG. 10 shows a fragmentary perspective view of a bone plate with theopening of FIG. 9.

FIG. 11 shows a top plan view of a further embodiment of an opening foruse in a bone plate.

FIG. 12 shows a fragmentary top perspective view of a bone plate withthe opening of FIG. 11.

FIGS. 13-17 show alternative shapes and types of bone plates that may beused with various embodiments of this invention.

FIG. 18 shows a cross-sectional view of an alternative embodiment of abone plate having a fastener with a finned head secured in the boneplate.

FIG. 19 shows a side elevation view of the fastener shown in FIG. 18.

FIG. 20 shows a top perspective view of the fastener of FIG. 19.

FIG. 21 shows a fragmentary top perspective view of a bone plate thatmay be used to receive the fastener of FIGS. 19 and 20.

FIG. 22 shows a cross-sectional view of the plate of FIG. 21.

FIG. 23 shows a side elevation view of a fracture being treated with abone plate and the fastener of FIG. 19.

FIG. 24A shows a side elevation view of an exemplary locking screwaccording to one embodiment of the present invention.

FIG. 24B shows a cross-sectional view of the locking screw of FIG. 24A.

FIG. 25A shows a top plan view of a portion of a bone plate, including ahole without the threads of the hole shown, according to one embodimentof the present invention.

FIG. 25B shows a cross-sectional view of the portion of the bone plateshown in FIG. 25A as viewed along line 25B-25B of FIG. 25A.

FIG. 25C shows a top plan view of the portion of the bone plate shown inFIGS. 25A and 25B, with the threads of the hole shown.

FIG. 25D shows a cross-sectional view of the portion of the bone plateshown in FIGS. 25A-25C as viewed along line 25D-25D of FIG. 25C.

FIG. 25E is an enlarged section view taken at inset circle 25E in FIG.25D.

FIG. 26 shows a cross-sectional view of the locking screw of FIGS. 24Aand 24B positioned in the bone plate shown in FIGS. 25A-25E.

FIG. 27 shows a side elevation view of an exemplary compression screwfor use according to one embodiment of the present invention.

FIG. 28 shows a cross-sectional view of the compression screw of FIG. 27positioned in the bone plate shown in FIGS. 25A-25E.

FIG. 29A shows a side elevation view of an exemplary locking screwaccording to an embodiment of the present invention.

FIG. 29B shows a cross-sectional view of the locking screw of FIG. 29A.

FIG. 30A shows a top plan view of a portion of a bone plate according toan embodiment of the present invention.

FIG. 30B shows a cross-sectional view of the portion of the bone plateshown in FIG. 30A as viewed along line 30B-30B of FIG. 30A.

FIG. 30C is an enlarged section view taken at inset circle 30C in FIG.30B.

FIG. 31 shows a cross-sectional view of the locking screw of FIGS. 29Aand 29B positioned in the bone plate shown in FIGS. 30A-30C.

FIG. 32 shows a cross-sectional view of the compression screw of FIG. 27positioned in the bone plate shown in FIGS. 30A-30C.

FIGS. 33-50 are views of various exemplary bone plate configurationsaccording to various embodiments of the present invention.

FIG. 51 shows a provisional fixation slot according to one embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention provide a fastener 10 for polyaxialfixation in a variety of different types of bone plate openings. FIGS. 1and 2 illustrate an embodiment of one such fastener. This applicationuses the terms “fastener” and “screw” interchangeably. Fastener 10includes a head 16 and a shaft 14 that defines a fastener central axis12. In FIGS. 1 and 2, the shaft 14 is threaded. The shaft 14 may befully threaded, partially threaded, comprise a helical blade, and/or maycomprise one or more tacks, deployable talons, expandable elements, orso forth. Any feature that allows shaft 14 to engage bone is consideredwithin the scope of this invention and may be referred to generally as a“threaded shaft” for the sake of convenience. It is also possible thatshaft 14 is not threaded, so that fastener 10 takes the form of a peg ora pin. This alternative embodiment may be preferred in certainprocedures where, for instance, the main goal is to prevent tilting of abone segment or in procedures where there is no concern of fastener 10pulling out from the bone and hence no need for shaft 14 to be threadedor otherwise configured to engage bone. The end of shaft 14 may be aself-tapping or self-drilling tip.

The head 16 of the fastener 10 also includes a fastener seating surface20. The fastener seating surface 20 may encompass the entire head 16 ofthe fastener 10, or it may only partially encompass the head 16. Forexample, in FIG. 1 the height of the fastener seating surface 20 is lessthan the height of the head 16, so that a portion of the head 16protrudes above the fastener seating surface 20. In other embodiments,however, the fastener seating surface 20 encompasses the entire head 16of the fastener 10. In some embodiments, at least portions of thefastener seating surface 20 are smooth and contoured, as shown inFIG. 1. The smooth portions 22 of the fastener seating surface 20 may beseen in FIGS. 1 and 2.

Fastener 10 will typically have a bore 18 for receiving a driver inorder to drive fastener 10 into the bone plate and into bone. The bore18 may be any size and shape, for example, it may have a hexagonalconfiguration to receive a corresponding hexagonal driver, a Phillipsscrew head, a flat-head, a star configuration, Torx, or any otherappropriate configuration that can cooperate with a driver to placefastener.

FIG. 2 illustrates fastener 10 engaged in a bone plate 40 having anupper surface 44, a bone contacting surface 42, and a threaded opening30 extending between the upper surface 44 and the bone contactingsurface 42. The terms “opening” and “hole” are used interchangeablyherein. More specifically, opening 30 of plate 40 is shown havingopening threads 32 and an opening central axis 36. Opening threads 32are typically any standard-type thread. For example, the opening threads32 may be a continuous ridge or a non-continuous ridge. It may comprisea portion of a revolution, one complete revolution, multiplerevolutions, a single lead, or multiple leads, or any other threadsknown in the art. Additionally or alternatively, opening threads 32 mayinclude any other surface that will engage with and seat with featuresof the fastener 10. For example, opening threads 32 may have a series ofdimples, ridges, bumps, textured areas, or any other surface that cansecure with features of the fastener 10 as described herein. In short,any type of thread is intended for use with various embodiments of thisinvention.

The fastener seating surface 20 may be formed of any material but it ispreferable that the fastener seating surface 20 be made of a materialwith a yield strength that is lower than that of the material definingthe opening 30. In some embodiments the fastener seating surface 20 ismade from polyethylene, for example.

In use, fastener 10 is positioned and rotated in opening 30. Rotatingthe fastener 10 with respect to the opening 30 causes deformation of thefastener seating surface 20 because the fastener seating surface 20 ismade from a material that is weaker than that defining the opening 30.More specifically, the opening threads 32 tap “threads” into the head 16of the fastener 10 (and more particularly the fastener seating surface20) and thereby fixes the orientation of the fastener 10 relative to theopening 30. The resulting threaded portions 24 on the fastener seatingsurface 20 are shown in FIG. 2. As may be seen from FIG. 2, there may besmooth portions 22 where the opening threads 32 have not tapped into thefastener seating surface 20. Thus in some embodiments the entire head 16of the fastener 10 may not be tapped. Additionally, the location of thesmooth portions 22 and the threaded portions 24 will change dependingupon the insertion angle 38 in which the fastener 10 is inserted.

Given that there are no pre-existing threads on the head of fastener 10,the fastener 10 may be inserted and locked into the opening 30 in anyangular orientation. Embodiments of the invention provide for aninsertion angle 38 between the fastener central axis 12 and the openingcentral axis 36. The insertion angle 38 may also be described as thedirection along which fastener 10 is inserted through opening 30 anddriven into bone material. In some embodiments the opening central axis36 and the fastener central axis 12 are co-linear so that the insertionangle 38 is zero. But in other embodiments the opening central axis 36and the fastener central axis 12 are not co-linear and the insertionangle 38 has some value. FIG. 2 has an insertion angle 38 that isapproximately 20-30°; however, other insertion angles 38 are within thescope of the invention.

The fastener 10 may be positioned in the opening 30 and fixed in theplate 40 at various insertion angles 38. This may help in capturing“renegade” or random bone fragments that have split from the bone duringfracture and in securing the bone fragments to the plate 40. Forexample, if a wrist bone is broken, there will be numerous fragmentsthat may shatter in various directions. Fastener 10 may be inserted intoplate 40 at various insertion angles 38 in order to capture the renegadefragments that would otherwise not be secured to a bone plate 40 usingonly a locking or a non-locking fastener.

Fastener 10 may be used in connection with any type of threaded hole(including, but not limited to, any threaded hole disclosed herein) onany type of bone plate. The bone plate may be adapted to contact one ormore of a femur, a distal tibia, a proximal tibia, a proximal humerus, adistal humerus, a clavicle, a fibula, an ulna, a radius, bones of thefoot, or bones of the hand. The bone plate may be curved, contoured,straight, or flat. It may be a periarticular plate or a straight plate.The plate may have a head portion that is contoured to conform to aparticular bone surface, such as a metaphysis or diaphysis, that flaresout from the shaft portion, that forms an L-shape, T-shape, Y-shape,with the shaft portion, or that forms any other appropriate shape to fitthe bone to be treated (not shown in figures).

The bone plate may be formed of titanium, stainless steel, cobaltchrome, plastic—such as polyetheretherketone (PEEK), polyethylene, ultrahigh molecular weight polyethylene (UHMWPE), or a carboncomposite—resorbable polylactic acid (PLA), polyglycolic acid (PGA),combinations or alloys of such materials or any other appropriatematerial that has sufficient strength to be secured to and hold bone,while also having sufficient biocompatibility to be implanted into abody. Although the above list of materials includes many typicalmaterials out of which bone plates are made, it should be understoodthat bone plates comprised of any appropriate material are within thescope of this invention.

In some embodiments, openings 30 may be provided on a bone plate 40 incombination with a variety of other types of openings (e.g., other typesof threaded openings, non-threaded openings, provisional fixation orK-wire holes, combination holes, etc.), including but not limited tothose discussed in reference to FIGS. 3-51. It should be understood thatthese various types of openings may be used on any type of bone plates,in any combination and in any size.

In one embodiment, such as shown in FIGS. 13 and 14, bone plate 40includes openings 30 in combination with finned openings 50. Embodimentswith finned openings 50 may be combined with a fastener 90. Fastener 90may have a shaft 92 with a longitudinal axis 96. As shown in FIG. 14,the shaft 92 may be threaded or non-threaded. In certain embodiments asshown in FIGS. 3 and 8, the head 94 of fastener 90 has at least one setof threads 98. Threads 98 are typically any standard-type thread. Forexample, the threads 98 may be a continuous ridge or a non-continuousridge. They may comprise a portion of a revolution, one completerevolution, multiple revolutions, a single lead, or multiple leads, orany other threads known in the art. Additionally or alternatively, head94 of fastener 90 may include any other surface that will engage withand seat within specific features of plate 40 (described further below).For example, head 94 may have a series of dimples, ridges, bumps,textured areas, or any other surface that can secure fastener 90 asdescribed herein. As will be described in more detail below, threads 98of head 94 are adapted to engage, associate with, or otherwise cooperatewith fins 56 of finned opening 50. In short, any type of threadedfastener head is intended for use with various embodiments of thisinvention.

Plate 40 of FIG. 13 has a finned opening 50 (shown in detail in FIG. 4)with an inner surface 54 from which a series of concavely indented,inwardly protruding fins 56 extend. Fins 56 extend into finned opening50 toward central axis 52. The bases 58 of fins 56 form a concaveportion 60 at or near a substantially round upper circumference 62 ofupper surface 44. (The term “round” circumference is intended to referto any round shape, such an a circle, an oval, an egg-shapedcircumference, or any other opening shaped to receive the head 94 of afastener 90.) The bases 58 of the fins 56 may all meet in substantiallythe same plane and then angle downwardly and inwardly at a similar angleor slope.

It bears noting that the concave portion 60 is smooth and non-threaded.In fact, there are not any threads on concave portion 60 or anywhere oninner surface 54 of finned opening 50. The lack of threads helps easethe manufacturing of plate 40, and allows plate 40 to be manufactured asthinly as desired.

The dimensions of fins 56 are typically dependent at least in part uponthe pitch and threads of fastener 90. For example, a larger plate 40 foruse with a larger fastener 90 (e.g., for use on a femur bone) willlikely be thicker and will have larger and thicker fins 56 than asmaller plate 40 (e.g., for use on a smaller bone). In specificembodiments, the fins 56 are particularly thin so that they can be movedup or down and deformed upon pressure. In some embodiments, the fins 56may be pressed toward the edges of the finned opening 50. A non-limitingexemplary range of thicknesses for fins 56 may be from about 0.5 mm toabout 5 mm, although larger and smaller sizes are possible. In theory,the fins 56 are intended to fit between threads 98 on the threadform offastener 90, as shown in FIG. 3.

Providing a non-threaded inner surface 54 also allows the fastener 90 tobe inserted into finned opening 50 at any desired insertion angle 38, asillustrated by FIG. 7. Embodiments of the invention provide for aninsertion angle 38 between the longitudinal axis 96 of the fastener 90and the central axis 52 of finned opening 50. The insertion angle 38 mayalso be described as the direction along which fastener 90 is insertedthrough finned opening 50 and driven into bone material. In someembodiments the central axis 52 and the longitudinal axis 96 areco-linear so that the insertion angle 38 is zero. But in otherembodiments the central axis 52 and the longitudinal axis 96 are notco-linear and the insertion angle 38 has some value. FIG. 7 illustratesone fastener 90 having an insertion angle 38 of approximately 0° andanother fastener 90 having an insertion angle 38 of approximately20-30°; however, other insertion angles 38 are within the scope of theinvention. Varying the insertion angle 38 is possible because there arenot any threads in the finned opening 50 to interfere with the desiredinsertion angle 38. The fins 56 are intended to slightly bend or deformin order to secure the fastener 90 in place in finned opening 50. Fins56 actually engage threads 98 or other surface of fastener 90.

Referring back to FIG. 4, in the embodiment shown, as fins 56 extendtoward central axis 52, they taper to form tapered sides 64. The fins 56end at rounded tips 66, although tips 66 can be pointed, square,rectangular, or any other appropriate configuration. For example, asshown in FIGS. 9 and 10, fins 56 may have straight edges or sides 70 andstraight ends 72. This embodiment shows fins 56 that are partiallyrectangular-shaped. The openings 74 between fins 56 are slit-shaped.

An alternate embodiment is shown in FIGS. 11 and 12, which illustratefins 56 with a more triangular shape. In this embodiment, fins 56 areshown having sides 80 that taper inwardly and end edges 82 that are flatand small, forming the apex area 84 where adjacent sides 80 converge.Openings 86 in FIG. 11 are wider than openings 74 in FIG. 9. Both setsof openings 86, 74 in these alternative embodiments are shown havingrounded backs 88, where they meet inner surface 54 of finned opening 50.It should be understood however, that these are merely examples of fin56 shapes and that any appropriate shapes are possible and consideredwithin the scope of this invention. Non-limiting examples includetrapezoidal, square, round, circular, triangular (with a pointed tipinstead of apex area 84), and any other possible option.

As shown in FIG. 6, the lower circumference 68 at the bone contactingsurface 42 of plate 40 may appear to be more jagged than the uppercircumference 62 at the upper surface 44 due to the fins 56 forming aportion of bone contacting surface 42. The lower circumference 68 canappear almost “flower-like,” meaning that each fin 56 appears to form apetal of the lower circumference 68. Alternatively, for the embodimentsof FIGS. 9-12, the lower circumference 68 will appear similar to theshape created by fins 56.

Although the figures show a finned opening 50 with about five to eightfins 56, it should be understood that any number of fins 56 isconsidered within the scope of this invention. For example, there may betwo or three fins 56, or ten or twenty or more fins 56, depending uponthe plate 40 for which the finned opening 50 is intended for use.

The primary purpose of fins 56 is to grasp one or more threads 98 of afastener 90 in order to secure the fastener 90 in place in the boneplate 40 at any desired insertion angle 38. For example, as opposed tothreaded openings 30 used with fastener 90 (which engage the threads 98of the head 94 of the fastener 90 in one way only, limiting thesurgeon's ability to angle the fastener 90 as desired), the fins 56 ofthis embodiment are still intended to secure the threads 98 of the head94 of fastener 90 in place, but at any insertion angle 38. Moreover, asshown in FIGS. 5-7, fasteners 90 need not be inserted at the sameinsertion angle 38. One fastener 90 may be inserted at a first insertionangle 38, and another fastener 90 may be inserted at a second, anddifferent, insertion angle 38. As a fastener 90 is inserted, its threads98 start to engage the fins 56, as shown in FIG. 3. As discussed above,the fins 56 may be very thin so that as the threads 98 start to grabfins 56, the fins 56 may move up or down as appropriate to engage thethreads 98 and secure the fastener 90 in the finned opening 50. Inshort, the threads 98 engage fins 56 so that the fins 56 fit between thethreads 98. This movement of fins 56 can be a permanent deformation, sothat the fins 56 cannot flex back and allow the fastener 90 to work itsway out.

As discussed above, finned openings 50 may be provided on all types ofbone plates 40 and may be combined with other types of openings,examples of which are shown in FIGS. 13-17. There may be a finnedopening 50, a threaded opening 30, and a provisional pin opening 102.Other options are holes that can be used with either a threaded ornon-threaded fastener, as well as combination slots 104. It should beunderstood that these various types of openings may be used on any typesof bone plates, in any combination and in any size. FIG. 14 shows aplurality of finned openings 50 in the head of bone plate 40. This mayhelp achieve better fixation of a fractured bone, because the fastener90 can be inserted at various angles to capture “renegade” or randombone fragments that have split from the bone during fracture, but stillsecure the bone fragments to the plate 40. For example, as shown in FIG.23 if a bone is broken, there will be numerous fragments that mayshatter in various directions. The plates 40 described herein can beused to place a fastener 110 at various angles in order to capture therenegade fragments that would otherwise not be secured to a bone plate40 using only a locking or a non-locking fastener. Although FIG. 23shows a fastener 110 with a finned head 112, the same concept applies toa fastener 90 and a finned opening 50. It should additionally beunderstood that other types of openings (in addition to or instead offinned openings 50) may be present in the head of the plate, as well aselsewhere on plate 40. Particularly suitable may also be openings 30 forreceiving fasteners 10, which also allow for polyaxial insertion andfixation.

As previously mentioned, fastener 90 may be any typical fastener, madeout of any appropriate material. It will typically have a bore 18 forreceiving a driver in order to drive fastener 90 through plate 40 andinto bone. The bore 18 may be any size and shape, for example, it mayhave a hexagonal configuration to receive a corresponding hexagonaldriver, a Phillips screw head, a flat-head, a star configuration, Torx,or any other appropriate configuration that can cooperate with a driverto drive fastener 90 into plate 40.

Turning now to the methods of implantation, the surgeon accesses thesurgical site of interest, which can be an internal site at which a bonefracture is located that requires stabilization to ensure properhealing. The fracture may be reduced with conventional forceps andguides (which are known to those in the art), and a bone plate 40 ofappropriate size and shape is placed over the fracture site. In someinstances, the bone plate 40 may be temporarily secured to the boneusing provisional fixation pins. In the bone plates 40 shown in FIGS. 13and 14, provisional fixation pins may be used through either theprovisional pin openings 102, or any other opening in the plate 40.Provisional fixation provides for temporarily securing the bone plate 40to the bone before placing fixation screws through the bone plate 40, sothat one can be certain the bone plate 40 is properly positioned beforeplacing bone screws for permanent fixation of the bone plate 40 to thebone. Moreover, with provisional fixation, x-rays can be taken of thebone plate/construct without excess instruments in the field of view.

Once the plate 40 is secured at a desired location in relation to thefracture (typically using one or more provisional fixation pins,although any other appropriate method may be used), the surgeon thenidentifies an insertion angle 38 (see FIGS. 2 and 7), or the directionalong which fastener 10, 90 is to be inserted through a selected opening30, 50 and driven into bone material. If bone plate 40 includes morethan one opening 30, 50 as shown in FIGS. 13-17, the surgeon alsoselects the specific opening 30, 50 to be used. After selecting thedesired insertion angle 38 and opening 30, 50, the surgeon inserts shaft14, 92 of fastener 10, 90 through opening 30, 50 until the tip contactsbone material. In some cases, a hole may need to be drilled or tappedinto the bone along the insertion angle 38 to facilitate the initialtapping or insertion of fastener 10, 90. The surgeon then uses anappropriate driving tool in the bore 18 of head 16, 94 to manipulate thefastener 10, 90 into place.

Because fastener 10, 90 may be inserted at angles other than alignedwith the central axis 36, 52 of opening 30, 50, fastener 10, 90 may beused to grab or secure bone fragments that are out of line with thetraditional angle at which a locking screw would normally be inserted.The surgeon may need to toggle or maneuver the fastener 10, 90 in orderto secure and draw in displaced bone fragments.

Once the bone fragment is secured, the fastener 10, 90 is ready to besecured to the plate 40. As fastener 10, 90 is driven further into boneit is also drawn further into plate 40. If fastener 10 is used in anopening 30, drawing the fastener 10 into the plate 40, for example byrotating the fastener 10 with a tool via the bore 18, causes deformationof the fastener seating surface 20 because the fastener seating surface20 is made from a material that is weaker than the threads 32 in theopening 30. This deformation allows “threads” to be tapped into the head16 of the fastener 10 and fixes the orientation of the fastener 10relative to the opening 30. If fastener 90 is used in finned opening 50,as threads 98 of fastener head 94 begin to contact fins 56, the fins 56are allowed to engage within the threads 98 to hold the fastener 90 inplace in the desired insertion angle 38, even angles that are other thanin line with the opening central axis 52. The action of engagementbetween fins 56 and threads 98 rigidly affixes fastener 90 to the boneplate 40 at the desired insertion angle 38.

In some embodiments, the surgeon may then use traditional locking and/ornon-locking screws in other openings 30, 50 on plate 40. This can helpfurther secure the bone plate 40 to the bone fracture if needed. Oneadvantage of opening 30 is that it is adapted to receive a fastener 10,90, other locking screws, or a non-locking screw.

In some instances, once all fasteners 10, 90 and/or screws are placed,the surgeon may place covers over the unused openings 30, 50particularly if there are any unused openings 30, 50 that cross thefracture in order to strengthen the plate 40. Additionally oralternatively, the surgeon may use bone graft material, bone cement,bone void filler, and any other material to help heal the bone.

FIGS. 18-22 illustrate an alternate embodiment of an opening andfastener that allows for polyaxial fixation. Plate 40 is provided withopenings 126 for receiving fastener 110, as shown in FIGS. 18-22. Thesefigures show a fastener 110 with a finned head 112. Specifically, thefinned head 112 comprises a bore 114 and at least one set of extendingfins 118 around a portion 120 of the finned head 112. Fins 118 are shownas being square or trapezoidally-shaped with tapered edges, althoughthey may be any other shape, such as rounded, oval, rectangular, curved,rhomboid, diamond-shaped, triangular or any other appropriate shape. Theedges of fins 118 may taper inwardly, outwardly, or be about parallelwith one another. Fins 118 may be provided in a single row around finnedhead 112 or layered in multiple rows as shown. If layered in multiplerows, each individual fin 118 may be directly above another fin 118 (sothe top of the fastener 110 looks like that shown in FIG. 20).Alternatively, each individual fin 118 in a lower layer may be offsetfrom a fin 118 in a higher layer. The number of fins 118 in a set mayalso vary from about two or three up to any desired number that can fiton portion 120 of finned head 112. As with the fins 56 of finned opening50 described above, the fins 118 are preferably quite thin, thethickness varying depending upon the use of fastener 110 and plate 40.For example, a larger fastener 110 for use with a larger plate 40 (e.g.,for use on a femur bone) will likely have larger and thicker fins 118than a smaller fastener 110 (e.g., for use on a smaller bone). Inspecific embodiments, the fins 118 are particularly thin so that theycan be moved up or down or compressed upon pressure. A non-limitingexemplary range of thicknesses for fins 118 may be from about 0.5 mm toabout 5 mm, although larger and smaller sizes are possible. In theory,the fins 118 are intended to fit between the threadform of plate 40.Fastener 110 may also have a shaft 122 that is threaded or unthreaded,as described above with respect to fastener 90.

Fastener 110 may be used with any bone plate that has a threadedopening. In one example (see FIGS. 18, 21, and 22), bone plate 40includes opening 126 provided with Acme threads 128 that have a morerectangular shape than the pointed, sharp threads that are typicallyused in bone plates. As shown in FIG. 22, opening 126 has threads 128that end at their edges 130 in a rectangular shape. Providing arectangular shape with a flatter edge 130 allows a larger channel forthe fins 118 to engage. In an even more specific embodiment, the threads128 may be angled at about 15-20° off of the central axis 132 of opening126, and even more specifically, at about 18° off of the central axis132. While Acme threads are disclosed, one of skill in the art willrecognize that any thread geometry may be provided in opening 126.

In use, fastener 110 is inserted into opening 126, the fins 118 engagethreads 128 and, much like the fins 56, fins 118 are very thin so thatas the threads 128 of plate 40 start to grab the fins 118, the fins 118may move up or down as appropriate to engage the threads 128 and securethe fastener 110 in place, as shown in FIG. 18. In most cases, thismovement of fins 118 is a permanent deformation, so that the fins 118cannot flex back and allow the fastener 110 to work its way out.

Other opening or plate hole geometries that may be provided in plate 40in any combination are illustrated in FIGS. 25A-E and 30A-C. Asdiscussed in more detail below, these holes or openings mayinterchangeably receive locking screws or fasteners as well ascompression screws or fasteners. They may also receive the fasteners 10discussed above. Plate 40 may also include non-threaded holes oropenings that receive only compression screws or fasteners.

FIGS. 24A and 24B show an exemplary uniaxial locking screw 140 for useaccording to one embodiment. Such a locking screw 140 includes athreaded head 142 and a threaded shaft 144. Locking screw 140 may be a3.5 mm, 4.5 mm, 6.5 mm, or other size locking screw, which is understoodby those skilled in the art. In the exemplary embodiment shown in FIGS.24A and 24B, the lead between the threads of head 142 and the threads ofshaft 144 is broken. The threads in shaft 144 of locking screw 140 aresingle lead and the threads in head 142 are triple lead, providinglocking screw 140 with the same pitch throughout. It is preferable, butnot required, for certain embodiments of locking screws 140 according tothis invention to have a constant pitch. In an exemplary 3.5 mm lockingscrew 140, the pitch is 1.25 mm and the angle of the thread form isabout 45° to about 60°. In an exemplary 4.5 mm locking screw 140, thepitch is 1.75 mm and the angle of the thread form is about 60°. Lockingscrew 140 also includes an internal hex head 146, as shown in FIG. 24B,that is used when tightening locking screw 140 into a bone plate and/orbone.

FIGS. 25A-25E show different views of a portion of a bone plate 40according to an embodiment of the present invention. Such bone platesgenerally include one or more holes or other openings, such as in theexemplary bone plates shown in FIGS. 33-50, which are briefly describedbelow. However, for ease of illustration and for purposes of describingan exemplary embodiment of the present invention, only a portion of boneplate 40 is shown in FIGS. 25A-25E.

The particular bone plate 40 shown in these drawings includes a hole 152extending through upper surface 44 and bone contacting surface 42 ofbone plate 40. FIGS. 25A and 25B show hole 152 without its threads tohelp illustrate certain aspects of this embodiment of the invention,while FIGS. 25C-25E show hole 152 with its threads. It should beunderstood that the geometry of hole 152 is the same throughout theseFigures, although the geometry of hole 152 is not as clearly visible inFIGS. 25C-E that show the threads of hole 152. As seen most clearly inFIG. 25B, hole 152 includes a top portion 158 extending downward fromupper surface 44. Top portion 158 is generally frustoconical in shapeand extends from upper surface 44 at an angle of θ1 relative to theplane of upper surface 44, as shown in FIG. 25B. In an exemplaryembodiment, angle θ1 is about fifty-two°.

A bottom portion 160 of hole 152 extends from the end of top portion 158to bone contacting surface 42 of bone plate 40. Bottom portion 160includes threads 162, as shown in FIGS. 25C-25E. Some of threads 162 mayextend into top portion 158 depending on the particular embodiment, buttop portion 158 is not completely threaded.

In the exemplary embodiment shown in FIGS. 25A-25E, bottom portion 160is tapered. The included angle, θ2 shown in FIG. 25B, of the taper ofbottom portion 160 may be less than about thirty°, including zero°(i.e., no taper at all). The larger the included angle, the larger hole152 in bone plate 40 must be, which begins to compromise the strength ofthe plate if the included angle θ2 is much larger than about thirty°. Inan exemplary embodiment, θ2 is about twenty°.

FIG. 26 shows a side view of locking screw 140 threaded into hole 152 ofbone plate 40. Head 142 of locking screw 140 is received by threads 162of bone plate 40. Threads 162 completely surround the threads of head142, and the top of head 142 is received completely within hole 152 suchthat head 142 of locking screw 140 sits flush with upper surface 44 ofbone plate 40. Shaft 144 of locking screw 140 is threaded into bone (notshown). Head 142 of locking screw 140 should be tapered such that itproperly mates with threads 162 of hole 152 of bone plate 40.Furthermore, a threaded portion of a head of a locking screw for usewith certain embodiments of this invention should have a taper generallycorresponding to the taper, if any, of the threads of the hole of thebone plate. Fasteners 10 with a seating surface such as shown in FIG. 1and disclosed above can also be used in the holes 152 to lock and securethe fastener 10 to plate 40 at varying angles within hole 152.

FIG. 27 shows a side view of an exemplary compression screw 170 for useaccording to an embodiment of the present invention. Compression screw170 includes a head 172 and a threaded shaft 174 for engaging a bone.Head 172 is preferably spherical, as shown in the drawings. FIG. 28shows compression screw 170 inserted within hole 152 of bone plate 40.As shown in FIG. 28, head 172 of compression screw 170 rides along topportion 158 of hole 152. As shown clearly in FIG. 28, the diameter ofshaft 174 is less than the diameter of the opening at bottom portion 160of hole 152. Thus, as shaft 174 is threaded into a bone (not shown),compression screw 170 may pull or push bone plate 40 in a particulardirection as the spherical head 172 of compression screw 170 comes intocontact with and rides along the top portion 158 of hole 152 of boneplate 40. The angle θ1, shown in FIG. 25B, at top portion 158 of hole152 is significant for compression of a fracture and is necessary tohelp shift the bone plate in the desired direction. If top portion 158were to extend straight down from upper surface 44 of bone plate 40,compression would be less successful. Compression screw 170 may movebone plate 40 in more than one direction as compression screw 170 isfully inserted within hole 152. In an exemplary embodiment, fineadjustment of fractures up to about two millimeters in severaldirections is possible.

FIGS. 29A and 29B show another exemplary locking screw for use accordingto an embodiment of the present invention. A locking screw 180 includesa head 182 and a threaded shaft 184. Similar to locking screw 140 shownin FIGS. 24A and 24B, locking screw 180 may be a 3.5 mm, 4.5 mm, 6.5 mm,or other size locking screw, which is understood by those skilled in theart, and the lead between the threads of head 182 and the threads ofshaft 184 is broken. The threads in shaft 184 of locking screw 180 aresingle lead and the threads in head 182 are triple lead, providinglocking screw 180 with the same pitch throughout. The pitches and anglesof thread form for exemplary 3.5 and 4.5 mm locking screws 180 aregenerally similar to those described above with reference to lockingscrew 140.

Locking screw 180 also includes an internal hex head 186, as shown inFIG. 29B, that is used when tightening locking screw 180 into a boneplate and/or bone. As may be seen from FIGS. 24 and 29, only a portionof head 182 of locking screw 180 is threaded, whereas the entire head142 of locking screw 140 is threaded. Additionally, the threaded portionof head 182 of locking screw 180 is not tapered, while head 142 oflocking screw 140 is tapered. These differences are because lockingscrew 140 is designed to mate with hole 152 of bone plate 40, whilelocking screw 180 is designed to mate with a hole 192 of a bone plate40, as further described below.

FIGS. 30A-30C show different views of a portion of a bone plateaccording to an embodiment of the present invention. As noted above,bone plates generally include one or more holes or other openings, suchas in the exemplary bone plates shown in FIGS. 33-50, but for ease ofillustration, only a portion of bone plate 40 is shown in FIGS. 30A-30C.

Bone plate 40 includes a hole 192 extending through upper surface 44 andbone contacting surface 42 of bone plate 40. Hole 192 includes a topportion 198 extending downward from upper surface 44. As shown in FIG.30B, one side of top portion 198 includes a ramp that extends from uppersurface 44 at an angle of θ3 relative to the plane of upper surface 44.In an exemplary embodiment, angle θ3 is about fifty-two°. The remainderof top portion 198 is a concave recessed portion that is generallyspherical in shape, as shown in FIG. 30B. Although of a slightlydifferent structure than top portion 158 of hole 152, top portion 198 ofhole 192 also has a generally frustoconical shape, as shown in thefigures.

A bottom portion 200 of hole 192 extends from the end of top portion 198to bone contacting surface 42 of bone plate 40. Bottom portion 200includes threads 202. Some of threads 202 may extend into top portion198 depending on the particular embodiment, but top portion 198generally has only the beginning of thread leads, if any threading.Unlike bottom portion 160 as shown in FIGS. 25A-25E, bottom portion 200in FIG. 30B is not tapered, but rather is generally cylindrical inshape.

FIG. 31 shows a side view of locking screw 180 threaded into hole 192 ofbone plate 40. Threads of head 182 of locking screw 180 are received bythreads 202 of bone plate 40. Threads 202 completely surround thethreads of head 182, and shaft 184 of locking screw 180 is threaded intobone (not shown). Head 182 of locking screw 180 is shaped such that itsunthreaded portion bears against the ramp of top portion 198 of hole 192of bone plate 40. Additionally, the threaded portion of head 182 isgenerally cylindrical (i.e., not tapered) so that it properly mates withthreads 202 of hole 192 of bone plate 40. A threaded portion of a headof a locking screw for use with certain embodiments of this inventionshould be shaped to generally correspond to the shape of the threadedportion of the hole of the bone plate.

FIG. 32 shows compression screw 170 inserted within hole 192 of boneplate 40. As shown in FIG. 32, head 172 of compression screw 170 sitswithin the frustoconical top portion 198, contacting the concaverecessed area of top portion 198 of bone plate 40. Head 172 ofcompression screw 170 contacts the ramp area of top portion 198, buthead 172 does not completely abut the ramp. As shown clearly in FIG. 32,the diameter of shaft 174 is less than the diameter of the opening atbottom portion 200 of hole 192. Thus, as shaft 174 is threaded into abone (not shown), compression screw 170 may pull or push bone plate 40in a particular direction as spherical head 172 of compression screw 170comes into contact with and rides along the frustoconical top portion198 of hole 192 of bone plate 40, similar to that described above withreference to FIG. 28. The angle θ3, shown in FIG. 30B, at top portion198 of hole 192 is significant for compression of a fracture and isnecessary to help shift the bone plate in the desired direction. If topportion 198 were to extend straight down from upper surface 44 of boneplate 40, compression would be less successful. Compression screw 170may move bone plate 40 in more than one direction as compression screw170 is fully inserted within hole 192. In an exemplary embodiment, fineadjustment of fractures up to about two millimeters in severaldirections is possible.

In practice, a first screw is initially inserted through a bone plateand into a bone on one side of a fracture and then a second screw isinserted through the bone plate on the opposite side of the fracture. Inan exemplary method according to an embodiment of the present invention,after the first screw is in place, a compression screw is insertedthrough a hole in the bone plate on a side of the fracture opposite theside of the first screw. The compression screw may be inserted throughthe hole and into the bone such that as the compression screw is fullyinserted, the bone plate is drawn over to a desired position. By movingthe bone plate, the tissue is being pulled together to reduce thefracture. Once the compression screw has been used to move the boneplate into the desired position, the compression screw may be removedfrom the bone and bone plate and a locking screw, which may, if desiredbe polyaxial (such as fastener 10), may be inserted through the hole inthe bone plate and in the bone in the space formerly occupied by thecompression screw. The locking screw can then be tightened to lock theplate into position. The replacement of the compression screw with thelocking screw is not required, but a locking screw may provide morestability and rigid fixation than leaving the compression screw inplace. In some modes of operation, a locking screw, which may bepolyaxial (such as fastener 10), is placed directly in a locking holewithout first inserting a compression screw in the hole. Certainembodiments of the invention contemplate using locking screws, some orall of which may be polyaxial or non-polyaxial, and compression screwsin any order and in combination or not in combination with each other.As described above, certain embodiments of this invention provide forfine adjustment of fractures in more than one direction.

FIGS. 33-50 show various exemplary bone plate configurations that mayinclude one or more openings or holes of any of the various geometriesdisclosed herein in any combination for receiving any of the variousfasteners or screws disclosed herein. Bone plates in accordance withembodiments of this invention can include threaded, non-threaded, and/orfinned openings 50 in any combination. Traditional locking screws 140,compression screws 170, and polyaxial fasteners 10 may be used with suchholes as appropriate. All holes in the exemplary plates of FIGS. 33-50include threads having any of the geometries disclosed herein or fins(not shown), while the other generally non-circular openings in theseplates may or may not include threads depending on the purposes forwhich the opening is to be used.

FIG. 33 shows a distal radius plate 205 that is applied on the volaraspect of the radius and used to treat fractures of the distal radius.FIG. 34 shows a distal tibia plate 210 used to treat distal tibiafractures and contoured to match the anatomy of the medial distal tibia.FIG. 35 shows a calcaneal plate 220 that is applied to the medial aspectof the calcaneus and used to treat calcaneal fractures. FIG. 36 shows adistal tibia plate 230 used to threat distal tibia fractures andcontoured to match the anatomy of the lateral anterior distal tibia.FIG. 37 shows a multipurpose plate 240 used in conjunction with thecalcaneal plate to fuse the talus to the calcaneus. FIG. 38 depicts adistal fibula plate 250 used to treat distal fibula fractures from thelateral side of the bone. FIG. 39 illustrates a bone plate 260 used totreat the medial distal humerus. FIG. 40 shows a proximal humerus plate270 contoured to match the anatomy of the lateral proximal humerus. FIG.41 illustrates a distal femur plate 280 contoured to treat fractures ofthe distal femur from the lateral side of the bone.

FIG. 42 shows a ⅓ tubular straight bone plate 290 used to treat smallbone fractures. FIG. 43 depicts a proximal tibia plate 300 contoured totreat proximal tibia fractures from the medial side. FIG. 44 shows areconstruction plate 310. FIG. 45 illustrates a small fragment straightplate 320, and FIG. 46 illustrates a large fragment bone plate 330. FIG.47 illustrates an olecranon plate 340 used to treat fractures of theproximal ulna. FIG. 48 shows a distal humerus plate 350 contoured tomatch the anatomy of the lateral posterior distal humerus. FIG. 49depicts a distal humerus plate 360 contoured to match the anatomy of thelateral distal humerus. FIG. 50 shows a proximal tibia plate 370contoured to treat proximal tibia fractures from the medial side that issimilar to plate 300, except that plate 370 includes only holes, such asholes 152 and 192 (shown in more detail in FIGS. 25 and 30,respectively) that may receive both compression and locking screws anddoes not include any other openings.

Shown in some of the exemplary bone plates in FIGS. 33-50 areprovisional fixation slots 380. FIG. 51 shows provisional fixation slot380 in a portion of a bone plate 40. As is well known to those skilledin the art, provisional fixation pins are commonly used to provisionallyaffix a bone plate to the bone prior to installation of the bone platewith permanent attachment, such as bone screws. Existing provisionalfixation slots typically allow only fixation of bone fragments and notany adjustability of the position of bone fragments. An embodiment of aprovisional fixation slot of this invention allows articulation of bonefragments in up to six degrees of freedom to reduce the bone fracture. Abone fragment may be locked into a position and then incrementallyrepositioned to another temporary or permanent location. In FIG. 51,slot 380 has a cross or X shape, but the shape of slot 380 may varyaccording to the desired functionality and may include I, L, T, andother shape slots.

In practice, a bone plate is placed on the bone and the plate may or maynot be affixed to the bone utilizing bone screws and/or provisionalfixation pins. When provisional fixation is desired, a provisionalfixation pin may be inserted through a provisional fixation slot anddriven into the target bone fragment. The fragment may be manipulated toreduce the fracture and draw the fragment to the plate. Once the bonefragment is in a desired position, the provisional fixation pin may betightened until the pin locks into the plate. If further movement of thebone fragment is desired, a second provisional fixation pin may beinserted in the same provisional fixation slot in a space in the slotthat is not occupied by the first pin. After insertion of the secondpin, the first pin may be removed and the bone fragment may bemanipulated with the second pin. Once a desired position of the bonefragment is reached, the second pin is locked into the bone plate.Standard devices well known to those skilled in the art, such as screws,pins, cables, and other devices, may be used to affix the bone to thebone plate. Once the construct is sufficiently stable, any provisionalfixation pins in use may be removed from the bone.

The foregoing description of exemplary embodiments of the invention hasbeen presented only for the purposes of illustration and description andis not intended to be exhaustive or to limit the invention to theprecise forms disclosed. Many modifications and variations to thestructures and methods recited above and shown in the drawings arepossible without departing from the scope or spirit of the abovedisclosure and the following claims. The embodiments were chosen anddescribed in order to explain the principles of the invention and theirpractical application so as to enable others skilled in the art to makeand utilize the invention and various embodiments and with variousmodifications as are suited to the particular use contemplated.Alternative embodiments will become apparent to those skilled in the artto which the present invention pertains without departing from itsspirit and scope.

1. A bone plate system for fixation of bone, the system comprising: a) abone plate comprising a bone contacting surface, an upper surface, and afirst opening comprising threads of a first material and extendingbetween the bone contacting surface and the upper surface; and b) afirst fastener comprising a head at least partially comprising apolymeric material that is softer than the first material, wherein, whenthe first fastener is inserted into the first opening, the threads ofthe first opening form threads in the polymeric material on the head ofthe first fastener to secure the first fastener in place at one of aplurality of possible angles within the first opening.
 2. The system ofclaim 1, wherein the polymeric material comprises polyethylene.
 3. Thesystem of claim 1, wherein the first material comprises titanium,stainless steel, cobalt chrome, plastic, polyetheretherketone,polyethylene, ultra high molecular weight polyethylene, resorbablepolylactic acid, polyglycolic acid, or combinations thereof.
 4. Thesystem of claim 1, further comprising a second fastener comprising ashaft for engaging bone and a head comprising a spherical portion,wherein the second fastener may be inserted in the first opening at aplurality of different angles.
 5. The system of claim 1, furthercomprising a second fastener comprising a shaft for engaging bone and ahead with threads configured and dimensioned to mate with the threads ofthe first opening, wherein, when the second fastener is inserted intothe first opening, the threads of the first opening and the threads onthe head of the second fastener engage.
 6. The system of claim 1,further comprising a second fastener comprising a shaft for engagingbone and a head having fins, wherein, when the second fastener isinserted in the first opening, the fins on the head of the secondfastener engage the threads of the first opening to secure the secondfastener in place at one of a plurality of possible angles within thefirst opening.
 7. The system of claim 1, wherein the first openingcomprises an axis and wherein the first opening is asymmetrical aboutthe axis.
 8. The system of claim 1, wherein the first opening comprisesa substantially frustoconical-shaped top portion adjacent the uppersurface of the plate and a bottom portion adjacent the bone contactingsurface of the plate, wherein the top portion of the first openingcomprises a non-threaded portion and wherein the bottom portion of thefirst opening comprises at least some of the threads.
 9. The system ofclaim 8, wherein the top portion of the first opening comprises a rampand a generally spherical-shaped recessed portion.
 10. The system ofclaim 8, wherein the top portion of the first opening further comprisesa threaded portion.
 11. The system of claim 8, wherein the bottomportion of the first opening is tapered.
 12. The system of claim 1,wherein the bone plate comprises a plurality of first openings.
 13. Thesystem of claim 1, wherein the bone plate further comprises a secondopening extending between the bone contacting surface and the uppersurface, wherein the second opening comprises a non-threaded opening.14. The system of claim 1, wherein the bone plate further comprises asecond opening extending between the bone contacting surface and theupper surface, wherein the second opening comprises a plurality ofprotruding fins.
 15. The system of claim 1, wherein the bone plate isadapted to contact a femur, a distal tibia, a proximal tibia, a proximalhumerus, a distal humerus, a clavicle, a fibula, an ulna, a radius,bones of the foot, or bones of the hand.
 16. A method of reducing afracture of a bone, the method comprising: a) reducing the fracture tobring bone fragments in close apposition; b) providing a bone platecomprising openings, wherein at least some of the openings comprisethreads; c) compressing the bone plate against the bone with a firstfastener to hold the fracture reduction; and d) inserting a secondfastener into one of the openings in the bone plate comprising threads,wherein the second fastener comprises a head at least partiallycomprising a polymeric material, and wherein, when the second fasteneris inserted into the opening comprising threads, the threads of theopening form threads in the polymeric material of the head of the secondfastener to secure the second fastener in place at one of a plurality ofpossible angles relative to the bone plate.
 17. The method of claim 16,wherein the first fastener is inserted before the second fastener. 18.The method of claim 16, wherein the first fastener is inserted after thesecond fastener.
 19. A method of reducing a fracture of a bone, themethod comprising: a) providing a bone plate comprising abone-contacting surface, an upper surface, and a first and secondopening extending between the bone-contacting and upper surfaces,wherein the first opening comprises threads; b) providing a firstfastener comprising a head, wherein the head comprises a polymericmaterial; c) inserting the first fastener through the first opening andon a first side of the fracture, wherein the threads of the firstopening form threads in the polymeric material on the head of the firstfastener to secure the first fastener in place at one of a plurality ofpossible angles within the first opening; and d) inserting a secondfastener through the second opening and into engagement with the bone ona second side of the fracture opposite the first side to adjustpositioning of the bone and surrounding tissue.
 20. A bone plate systemfor fixation of a bone, the system comprising: a) a bone platecomprising an upper surface, a bone contacting surface, and a firstopening extending between the bone contacting surface and the uppersurface, wherein the first opening comprises a substantiallyfrustoconical-shaped top portion adjacent the upper surface of the plateand a bottom portion adjacent the bone contacting surface of the plate,wherein the top portion comprises a non-threaded portion and wherein thebottom portion comprises threads made of a first material; and b) afirst fastener comprising a head and shaft for engaging bone, wherein aportion of the head comprises a polymeric material that is softer thanthe first material, wherein, when the first fastener is inserted intothe first opening, the threads of the first opening form threads in thepolymeric material of the head of the fastener.
 21. The system of claim20, wherein the polymeric material comprises polyethylene.
 22. Thesystem of claim 20, wherein the first material comprises titanium,stainless steel, cobalt chrome, plastic, polyetheretherketone,polyethylene, ultra high molecular weight polyethylene, resorbablepolylactic acid, polyglycolic acid, or combinations thereof.
 23. Thesystem of claim 20, further comprising a second fastener comprising ashaft for engaging bone and a head comprising threads, wherein, when thesecond fastener is inserted into the first opening, the threads on thehead of the second fastener engage with the threads of the firstopening.
 24. The system of claim 20, further comprising a secondfastener comprising a shaft for engaging bone and a head comprising aspherical portion, wherein, when the second fastener is inserted intothe first opening, the spherical portion of the head abuts the topportion of the first opening.
 25. The system of claim 20, wherein thefirst opening comprises an axis and wherein the first opening isasymmetrical about the axis.
 26. The system of claim 20, wherein thefirst opening comprises an axis and wherein the top portion comprises aramp extending from the upper surface at an angle to the axis.
 27. Thesystem of claim 20, wherein the top portion of the first opening furthercomprises a generally spherical-shaped recessed portion.
 28. The systemof claim 20, wherein the top portion of the first opening furthercomprises a threaded portion.
 29. The system of claim 20, wherein thebottom portion of the first opening is tapered.
 30. The system of claim20, wherein the bone plate comprises a plurality of first openings. 31.The system of claim 20, wherein the bone plate further comprises asecond opening comprising a non-threaded opening.
 32. The system ofclaim 31, wherein the bone plate comprises a plurality of secondopenings.